The present invention relates to axle assemblies for mounting wheel hubs to handlebar-steered vehicles, and more particularly to an axle assembly that securely mounts a wheel hub to a suspension fork to provide a torsionally stiffer front suspension assembly.
Typically, in handlebar-steered vehicles like bicycles and motorcycles, an axle assembly is used to mount a wheel hub to a fork. The fork includes parallel legs that extend upward from each side of the axle and connect at the top of the wheel at a central steering tube that forms part of the bicycle or motorcycle frame. The bottom end of the fork legs are typically u-shaped or annular dropouts shaped for receiving the axle assembly. The axle may be mounted to the dropouts with a quick-release mounting device. Such devices facilitate removal of the wheel for repairs, transport, storage, etc.
During a typical ride, a rider will encounter irregularities in the terrain that are transmitted through the wheel and fork to the handlebars. The rider may counteract these irregularities by steering. For the steering to be effective, it must be transmitted as directly as possible to the wheel. For this to occur, the wheel must be securely and rigidly mounted to the fork assembly.
Terrain irregularities create high loads at the front wheel/axle/fork interface, loads that are further heightened in off-road bikes, requiring even higher torsional rigidity at the wheel/fork/axle interface. To meet these heightened needs, bicycle axle design has slowly migrated toward motorcycle axle design. However, bicycle axles still need to avoid the drawbacks of increased weight and higher cost inherent to motorcycle axles, while continuing to embrace a tool-less, quick-release design.